Piano action



Sept. 8, 1964 Filed June 16, 1961 flV/////////////////////l C. W. ANDERSEN ETAL PIANO ACTION 2 Sheets-Sheet 1 sept. s, 1964 C. ANDERSEN ETAL PIANO ACTION 2 Sheets-Sheet 2 Filed June 16, 1961 INVENTORS.

erfg 5MM Hf/70rd M @202715615 United States Patent O 3,147,659 PANOACTION Clifford W. Andersen and Phillip 3. Roehrig, De Kalb, Ill., assignors to Thek Wurlitzer Company, Chicago, Ill., a corporation of Ohio v Filedlune 16, 1961, Ser. No. 117,592 Claims. (Cl. 84-240) This invention relates to panovactions.

As isA well known, the hammer of a piano action is caused to strike its corresponding string by the pivotal movement of a part called a ily or jack; and according to conventional practice, the fly is fulcrumed on a pivotal Whipby meansof a separately provided fly llange. Ordinarily, the lly llange is a generally H-shaped part which straddles both the whip and the lly. Because of this relationship, thev width ofthe lly isnecessarily limited; and this limitation restricts the possible area of contact betweenthe ily and the buttof the hammer. A restricted area of Contact at this important point tends to cause packing andgouging of the butt-facing material and eventual loss of smoothness in the operation of the piano action.v Furthermore, accurate spacing and parallelism of the whip pivot boreA and'v the fly pivot bore is made quite difficult by the provisionV of a separate ilyv flange. If the spacing is'not accurately maintained from action to action, the'weightof touch of the'k'eys will vary appreciably.

If parallelism is not maintained, the ll'y will tend to lie partly outside of the plane ofthe whip and the actuation of the hammer by the llywillbe-adversely affected.

Therefore, an important'object of the present invention is to provide a piano action which overcomes the limitations of ,the` prior art by incorporating an integral whip and ily llange.

Even when the conventional 'piano action incorporates an integrally formed whip andy lly'llange, there still is a need for frequent adjustment of the action in the course of use, particularly because of the fly rubbing across the regulating button that is employed to cause the required pivoting ofthe fly. Accordingly, another important` object of the present invention` is to provide a piano action which is arranged to minimize movement of the ilyl across the. surface of the regulating button.

A moreY general object of the invention is to provide a new andimproved piano action. i

Yet' another object of the invention is to provide a piano action that requires only infrequent regulation.

Still another objectk of the invention is to provide a piano action which is characterized by a. highly uniform performance of the keys.

A further object of the invention is to provide a piano action in ywhich there is no sensation of drag. in the` key touch.

A still further object of the invention is to provide a piano actionA in which. there is a positive, powerful: actuation of the hammer.

And a still further object of the invention isto provide a, piano action that. is amenable to a greater range of eX- A pression.

Additional'objects and features of the invention pertain to the particular structure and arrangements whereby the above objects are attained..

A piano action constructed in accord with the invention includes a rigidly positioned mainrail; a regulating rail arrangement spaced apart from the mainrail and including a regulating rail button; a unitary whip'and fly llange arrangement pivoted about a llxedl axis adjacent the mainrail, the unitary whip and fly. flange arrangement defining a pivot yaxis'for a fly; a lly swin-gably mounted on the unitary arrangementiat the pivot axis therefor, the, fly including a laterally extending portion abuttable with the regulating rail button, the fixed pivot axis for the unitary arrangement, the pivot axis for the fly, and the point of Contact between the ily and the regulating rail button being disposed in straight-line relationship at the threshold of actuation of the piano action.

The invention, both to its :structure and mode of operation, will be better understood by reference to the following disclosure and drawings forming a part thereof, wherein:

FIG. l is a side elevational view partially in cross-section of a piano action constructed in accord with the invention and showing the parts as they would appear at the threshold of actuation of the piano action;

FIG. 2 is a view similar to the showing of FIG. 1 but illustrating the arrangement of the parts as they would appear upon the hammer striking its string;

FIG. 3 is a side elevational view showing the fly mounted to the combined whip and lly llange, illustrating in particular the geometry involved in the operation of the parts; and

FIG. 4 is a perspective View of the combined whip and fly flange of the invention.

Referring now in detail to the drawings, specilically to FIG. l, the structure of an upright piano will be seen to include a keyboard lll and a frame 12. In compliance with conventional practice, a plurality of piano keys, such as the piano key 14, is fulcrumed on a balance rail, not shown, the balance rail being mounted on the keybed 10. A felt stop 16 is positioned between the keybed 10 and the key 14 resiliently to arrest downward movement of the rear end of the key.

A string plate 18 is suitably fastened to the frame 12 for supporting a piano string 20; and depression of the piano key 14 is arranged tocause striking of the corre- Vsponding string 20 through a piano action indicated generally by the numeral 22. The piano action 22 is mounted in the piano structure by means of a number of action brackets 24, each of which is securely fastened in the piano structure by suitable means. A mainrail 26, a spring rail 28 and a hammer rail 30 extend laterally through the piano structure to be affixed to each of the action brackets 24 for purposes of supporting the individual action members. Moreover, a regulating rail 32 extends laterally through the piano structure and is aiiixed to the mainrail 26 by means of mounting elements 34.

The piano action 22 includes a hammer 36 Which is mounted to a butt 38 by a hammer shank 49, the butt 38 being pivotally mounted to the mainrail 26 by a butt llange 42. Depression of the piano key 14 is arranged to actuate the hammer 36 by means of a sticker or abstract 44 one end of which is alllxed to piano key 14 by means of a keyfork 46, a rubber grommet 48 and a screw element 50. The other end of abstract 44 is pivotally mounted to a unitary Whip and ily flange member indicated generally at 52. Specifically, the abstract 44 is provided with a tongue portion 54 which is slidably received in an axial slot 56 formed in the end of the member 52. A pin 58 passes through aligned bores in the member 52 and in the abstract 44 pivotally to couple -these elements together.

The combined Whip and ily llange member 52 is swingably mounted to the mainrail 26 by means of a whip ilange 60. Whip ilange 60 is provided in an inverted, generally U-shaped conliguration. The spaced apart arms of the llange 60 straddle member 52 and operate in generally circular shaped recesses 62 fashioned in the opposite lateral sides thereof. A pin 64 enters aligned bores inthe member S2 and in the Whip llange 60 to provide the requisite pivotal mounting.

In accordance with an important feature of the invention, the member 52 includes an integral, fly-mounting projection 66 which extends laterally from a line joining the pivot axes defined by the pins 58 and 64. The ilyythe axis of pin 76 as the member 52.

v ponent parts cooperate.

allinea@ risV coupled to the member 52 straddling the ily-mounting projection 66. Therefore, the ily 74 is capable of taking the same overall dimension or width in the direction of It will be recognized that this arrangement establishes the practical maximum width for the fly 74 within the space limitations required of a single piano action and serves to eliminate gouging or dimpling of the resilient material that is employed as a facing for the butt 38.

The ily 74 includes an integral, laterally extending velement '78 which deiines a convex surface 80. A'reglulating rail button 82 is mounted to the regulating rail 32 by means of an eye screw 83, regulating rail button 82 overlying the curved surface 80 in confronting relationship. A felt pad 84 yis aiiixed to the regulating rail button S2 to be contacted by the surface 80. A compression spring 86' is disposed with its opposite ends situated in appropriately fashioned, confronting recesses in the element 7S and in the member 52 so as to` bias the curved surface 80 in the direction of the felt pad 84.

WithV reference to the position of the parts shown in FIG. l, it is important to note that the pivot axis of the member 52 that is delined by the pin 64, the pivot axis of the fly 74 that is defined by pin 76, and the point of contact between the curved surface 80 and the felt pad84 are arranged to fall along a straight line indicated at 88. The purpose of this arrangement will become apparent hereinafter.

A' depression of piano key 14 causes projection of the hammer 36 into striking engagement with the string 20, force lbeing transmitted from the piano key 14 through ,the abstract 44, the member 52 and the ily 74 which eccentrically engages the butt'38. Advantageously, the

'butt 38 is faced with felt in theY region contacted by the fly. Upon return of the hammer 36 from striking v engagement with the string 20, a catcher element 90 which is mounted to the butt 38 is trapped against a backcheck 92,-backcheckY 92 being mounted to member 52 in upstanding relationship by means of a backcheck rod 94. In addition, a spoon 96 mounted to member 52 is arranged to operate a damper lever 98 so as to retract a damper head 100 from contact with the piano string Z in advance of the hammer 36 striking the string.

For purposes of affording a more complete understanding of the invention, it is advantageous now to provide a functional description of the mode in which the com- Therefore and continuing with reference to FIG. l, previous reference has been made to j the fact that the center or axis of pin 64, the center or axis of pin 76 and the point of contac-t between the curved surface 80 of fly 74 and the felt pad 84 on the regulating button 82 are aligned in straight-line relationship at the start of escapement of the piano action 22, i.e. at the threshold of actuation of the piano action. Upon depression of the piano key 14, the end of member 52 which is associated with pin 58 is lifted by the abstract 44, the member 52 pivoting about the pin 64. Because fly 74 is pivoted about pin 76 and because the curved surface 80 of the laterally extending element '73 abuts the regulating button 82, this pivoting action of the member 52 results in a pivoting action of the fly 74 about the pin 76. This motion is transmitted to the butt 38 causing hammer 36 to be projected against the string 20.

After the depression of piano key 14 has initiated operation of the piano action 22, i.e. after escapement, the

`button felt.

4 point of contact between the curved surface and the regulating button is moved out of alignment With the centers of pins 64 and 76, as is shown in FIG. 2. However, this movement of the point of contact relative to the pins 64 and '76 is accompanied only by very minute movement of the curved surface 80 relative to the face of the pad 84.

As is shown in FIG. 3, the arc of movement of the fly pin center traverses the angle a. The relocated iy pin center is shown at 76. When arcs are drawn about the two positions of the fly pin center, using as a radius the initial spacing between the fly pin center and the point of contact of the ily with the regulating button, the arcs 102 and 102 are generated. Arc 102 is drawn about the fly pin center at the start of escapement Whereas the arc 102' is drawn about the ily pin center-at its maximum upward position.

As will be seen from an inspection of FIG. 3, the arcs 102 and 102 appear to intersect at the point of contact between the surface 80 and the regulating button, which point has been designated 104 for reference. Thus, the

geometry of member 52 and the fly 74 serves to minimize' the amount of movement of the surface 80 relative to the regulating button. In practice, the actual amount of sliding movement between the curved surface 80 and the pad 84 on regulating button S2 is negligible, being on the order of a few thousandths of an inch.

This minute amount of sliding movement produces only iniinitesimal wear on the regulating button. Correspondingly, there is a reduced need for regulating the piano action in order to adjust for wear on the regulating Furthermore, the negligible movement between the surface 80 of the y and the regulating button produces but a low frictional force at the instant of escapement. Accordingly, there is no sensation of drag upon depression of the piano key. Moreover, this low friction permits more power to be applied directly to the hammer, resulting in a greater range of expression for the pianist. Y Y

It is also important to observe that, by providing the member 52 with an integral, fly-mounting projection instead of using a separate y flange, boring of the holes for pins 58, 64 and 76 can be performed in aV single machine operation. The corresponding pin bores are shown in FIG. 4 at 106, 108 and 110 respectively. Boring of these three holes in a single operation achieves great accuracy in the spacing and parallelism ofthese holes. By accurately establishing and maintaining the positioning and parallelism of the holes 106, 108 and 110, a high degree of uniformity'in performance between the various keys in a piano isV achieved. Both the weight of touch of the keys and the amount of movement at the front end of the keys are held within tight tolerances.

The specific example herein shown and described should be considered as illustrative only. Various changes in structure will, no doubt, occur to those skilled in theV art; and these changes are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows: l 1.'In a piano action, the combination comprising:Y a

. rigidly positioned mainrail; regulating means spaced apart I from said mainrail; combined whip and ily flange means pivoted about a xed axis situated adjacent said mainrail, said combined means including a pivot axis fora fly parallel to and accurately spaced apart from said fixedV axis; and a fly swingably mounted on said combined means at Y saidV pivot axis, said fly including a laterally extending 2. In a piano action, the combination comprising: a rigidly positioned mainrail; actuating means spaced apart from said mainrail and including a key and an abstract; regulating means intermediate said mainrail and said actuating means; a unitary member defining a link pivotally mounted at one end to said mainrail about a rst axis and pivotally mounted at the opposite end to said abstract about a second axis, said member further defining a fly-mounting projection including a third axis spaced apart from a line joining said first and second axes, said third axis being accurately positioned with respect to said first axis; and a iiy mounted on said member to pivot about the said third axis, including a laterally extending element abuttable with said regulating means, wherein said first and third axes are aligned with the point of contact between said fly and said regulating means at the start of escapement of said piano action.

3. In a piano action, the combination comprising: a rigidly positioned mainrail; actuating means spaced apart from said mainrail and including a key and an abstract; regulating means intermediate said mainrail and said actuating means; a unitary member defining a link pivotally mounted at one end to said mainrail about a first axis and pivotally mounted at the opposite end to said abstract about a second axis, said member further defining a fiymounting projection including a third axis spaced apart from a line joining said first and second axes, said third axis being accurately positioned with respect to said first axis; and a fly mounted on said member to pivot about said third axis, including a laterally extending element defining a curved surface abuttable with said regulating means, wherein said first and third axes are aligned with the point of contact between said curved surface and said regulating means at the start of escapement of said piano action.

4. In a piano action, the combination comprising: a rigidly positioned main rail; actuating means spaced apart from said mainrail and including a key and an abstract; regulating means intermediate said mainra-il and said actuating means; a unitary member defining a link pivotally mounted at one end of said mainrail about a first axis and pivotally mounted at the opposite end to said abstract about a second axis, said member further defining a fiymounting projection including a third axis spaced apart from a line joining said first and second axes, said third axis being accurately positioned with respect to said first axis; and a fiy mounted on said member to pivot about said third axis, including a laterally extending element abuttable with said regulating means, said fiy having an axial slot opening generally from one end to receive said fly-mounting projection in straddled relationship, wherein said first and third axes are aligned with the point of contact between said fiy and said regulating means at the start of escapement of said piano action.

5. ln a piano action, the combination comprising: a rigidly positioned mainrail; regulating means spaced apart from said mainrail; whip means pivoted about a fixed axis situated adjacent said mainrail; and a fly mounted on said whip means to swing about a pivot axis, said iiy including a laterally extending portion abuttable with said regulatingr means, wherein said fixed axis, said pivot axis, and the point of contact between said laterally extending portion and said regulating means are disposed in straightline relationship at the threshold of actuation of said piano action.

References Cited in the file of this patent UNITED STATES PATENTS 238,214 Chase Mar. 1, 1881 322,089 Brambach July 14, 1885 519,611 Maurer May 8, 1894 587,543 Becker Aug. 3, 1897 594,476 Kidd Nov. 30, 1897 847,223 Ammon Mar, 12, 1907 987,723 Hutchinson Mar. 28, 1911 993,478 Vogel May 30, 1911 1,091,858 Mayor Mar. 3l, 1914 1,188,947 Klein June 27, 1916 1,296,826 Lingsch Mar. 11, 1919 2,061,154 Heitzmann Nov. 17, 1936 2,073,361 Bridges' Mar. 9, 1937 2,270,426 Farny Jan. 20, 1942 2,917,962 Ballett Dec. 22, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,147,659 I i september 1964 Clifford w. Andersen ep a1.

It is hereby certified that error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below 'below line 4l, insert `l 2,963,934 Hucke et al Signed and sealed .this 23rd `day of :March 1965.

(SEAL) Attest:

- ERNEST w. swIDER I EDWARD J. BRENNER Aitcsting Officer Commissioner of Patents Y UNITED STATES PATENT oEEICE CERTIFICATE 0F CORRECTION Patent No. 3,147,659 l September 8, 1964 Clifford W. Andersen et al.

It s hereby certified that error appears in the above numbered petent requiring correction andthat the said Letters Patent should read as corrected below.

Column 2, line 24, l for "keyboard" read keybed column 5, line 39, for 'fend of" read end to column 6, 'below line 4l, insert 2,963,934 Hucke et al signed and sealed ,this 23rd day of March 1965.

(SEAL) Attest:

Y ERNEST w. swIDER EDWARD J. BRENNER Aitesting Officer Commissioner of Patents 

5. IN A PIANO ACTION, THE COMBINATION COMPRISING: A RIGIDLY POSITIONED MAINRAIL; REGULATING MEANS SPACED APART FROM SAID MAINRAIL; WHIP MEANS PIVOTED ABOUT A FIXED AXIS SITUATED ADJACENT SAID MAINRAIL; AND A FLY MOUNTED ON SAID WHIP MEANS TO SWING ABOUT A PIVOT AXIS, SAID FLY INCLUDING A LATERALLY EXTENDING PORTION ABUTTABLE WITH SAID REGULATING MEANS, WHEREIN SAID FIXED AXIS, SAID PIVOT AXIS, AND THE POINT OF CONTACT BETWEEN SAID LATERALLY EXTENDING PORTION AND SAID REGULATING MEANS ARE DISPOSED IN STRAIGHTLINE RELATIONSHIP AT THE THRESHOLD OF ACTUATION OF SAID PIANO ACTION. 